Huffington Post sold for $315 million, which means Arianna got ~6.6% of the sale. That's not a huge chunk of the company, but it's not tiny. Jack Dorsey only owns 4.9% of Twitter, and he came up with the idea for Twitter.

The Huffington Post sale is pretty old news at this point, but the information in the document is interesting to anyone that follows the industry.

Here are two other details from the documents:

Huffington Post had just $5 million in cash on its balance sheet at the time of the sale.

Huffington Post was projected to do $60 million in revenue for 2011, and $10 million in EBITDA. It was projected to grow to $165 million in revenue by 2013, with $58 million in EBITDA